Penn State food scientists recruited a total of 292 regular ice-cream consumers to take part in the blind taste tests to determine their overall acceptability of various fat levels in fresh ice cream and to see if they could tell the difference between samples.

They changed the fat content by adjusting the levels of cream and by adding maltodextrin, a mostly tasteless, starch-based material that is used to add bulk to products, such as frozen desserts. Maltodextrin is not necessarily a healthy fat replacement alternative, according to the researchers.

In a series of taste tests, participants were unable to distinguish a 2 percent difference in fat levels in two vanilla ice cream samples as long as the samples were in the 6 to 12 percent fat-level range. While the subjects were able to detect a 4 percent difference between ice cream with 6 and 10 percent fat levels, they could not detect a 4 percent fat difference in samples between 8 and 12 percent fat.

According to lead author Laura Rolon, the most important finding in the study was that there were no differences in consumer acceptability when changing fat content within a certain range. "There is a preconception of 'more fat is better,' but we did not see it within our study."

The researchers also found that fat levels did not significantly sway consumers' preferences in taste. The consumers' overall liking of the ice cream did not change when fat content dropped from 14 percent to 6 percent, for example.

Researcher John Hayes said that perception and preference are often two separate questions in food science.

"Another example of this is how some people might like both regular lemonade and pink lemonade equally," said Hayes. "They can tell the difference when they taste the different lemonades, but still like them both. Differences in perception and differences in liking are not the same thing."

The study may challenge some ice cream marketing that suggests ice cream with high fat levels are higher quality and better tasting products, according to researchers.